Deadhorse #1

It's hard to let things go.  But if we're ever going to teach deeper and better, we've got teach fewer topics.  So here's the beginning of a list:

Rationalizing the denominator.  Time to kill it.  Call it dead.  

A bit of history:  this topic only exists because armed with a square root table and a piece of paper, it is easier to scratch out root-2 divided by 2 than 1 divided by root-2.  In other words, this topic has the same shelf life as interpolating on log tables. (Which I learned.  Despite the TI SR-52 sitting on my desk.)

You say some nice things about this topic.  You can connect it to other ideas.  But it doesn't have a point and its time to kill it.